With its first self-financed production, Marvel has produced one of the best superhero movies ever made, pure popcorn pleasure for its special effects, its story, its villain, and its hero. Director Jon Favreau, star Robert Downey Jr. and a first-class screenplay mix electrifying action, a compelling drama, and top-notch performances. Plus there are the best robot-type characters since R2D2, C3PO, and Hewey, Dewey, and Louie.

Downey plays international weapons dealer/super-brain/playboy Tony Stark as a rock star. He is an industrialist who appears on the cover of Rolling Stone and dates cover girls. He has an answer for every possible question or criticism about the company he runs: “The day weapons are no longer needed to keep the peace I’ll start building beams for baby hospitals.” But he does not have an answer for himself. His own conflicts would haunt him if he would slow down for a moment to think about them. That moment comes when he is captured by jihadists on a sales tour of American armed forces in the Mideast, using his own weapons. Told to recreate his company’s most powerful weapon for them instead he creates something for himself. The mastermind of cutting edge technology reaches back to the oldest of old school combat and creates for himself a high-tech suit of armor so that he can escape. It becomes the first stage in what will transform him into Iron Man. And the more he is protected by his Iron Man suit, the more he begins to open up to himself and others about who he really is and take responsibility for the world he has helped to create.

Downey superbly conveys Stark’s vulnerability and brilliance. He makes every line of dialogue feel improvised and natural, a great counter to the over-the-top special effects and fight scenes. In this middle of this great big movie he gives a subtle performance that is every bit as compelling as the most jam-packed action footage. He evolves as the suit does, trying out new things, coming alive for the first time as he is encased in metal.

The themes of the story has some powerful resonance about America’s role in the world without being heavy-handed. There’s no time for it — everything moves quickly as Stark continues to develop his suit and is attacked by bad guys and good guys and, well, there’s another category I am not going to give away. There is strong support from Terrence Howard as Stark’s military contact and friend, Gwenyth Paltrow, who gives some snap to her role as the indispensable aide de camp, and Jeff Bridges (with his head shaved!) as Stark’s closest business associate. The visuals are bracing and powerful and the action scenes are fanboy heaven. Watch for quick cameos from director Favreau, fan Ghostface Killah, and Iron Man co-creator Stan Lee. But don’t get distracted. Downey is the literal heart of this movie, and like the appliance that keeps Stark alive, he is a power source whose potential seems limitless.